PhoneGap is a framework for developing mobile apps and websites.
The idea behind PhoneGap is that an application needs to be compatible with all mobile platforms.
This is very good, hence the ongoing developer trend for supporting only iOS.
It supports numerous features in cross-platforms, and you only need to know JS, HTML, and CSS to work with the framework.
Best of all, there are community-built tools for this framework, notably, a cross-platform simulator.
The only downside to PhoneGap is the poor compatibility for some select features (file system IO only works on Android, no SMS API for Android, etc).















